Factors associated with lung cancer in COPD patients

Figures & data

Table 1 Demographic details and comorbidities for the patient cohort at the time of the COPD diagnosis (n (%) and mean±SD)

Variables	Lung cancer (N=594)	No lung cancer (N=19,300)	p-value
Women	303 (51.0)	10,139 (52.5)	0.48
Age	68.9±8.5	68.0±11.4	0.08
Single	122 (27.1)	4,931 (31.4)	0.06
Annual income × 1,000 SEK	139±95	145±142	0.44
Higher education level	175 (38.9)	7,259 (46.2)	0.002
Asthma	61 (10.3)	3,536 (18.3)	<0.001
Hypertension	109 (18.4)	4,457 (23.1)	0.006
Heart failure	26 (4.4)	1,860 (9.6)	<0.001
Myocardial infarction	21 (3.5)	896 (4.6)	0.23
Stroke	29 (4.9)	1,177 (6.1)	0.26
Diabetes	45 (7.6)	1,685 (8.7)	0.38
Osteoporosis	15 (2.5)	517 (2.7)	>0.99
Depression	27 (4.6)	1,752 (9.1)	<0.001

Abbreviation: SEK, Swedish Krona.

Table 2 The association between demographic variables and comorbidities with the risk of developing lung cancer assessed by univariate Cox regression

Variables	HR	95% CI	p-value
Gender	1.10	(0.93–1.29)	0.27
Age per 10 years	1.22	(1.13–1.32)	<0.001
Single	0.90	(0.73–1.11)	0.31
Income*	1.00	(0.93–1.08)	0.98
Education (high vs low)*	0.74	(0.61–0.89)	0.002
Asthma	0.54	(0.41–0.73)	<0.001
Hypertension	1.03	(0.87–1.23)	0.70
Heart failure	0.90	(0.73–1.12)	0.35
Myocardial infarction	1.16	(0.88–1.53)	0.30
Stroke	0.88	(0.66–1.17)	0.38
Diabetes	1.00	(0.79–1.28)	0.96
Osteoporosis	1.16	(0.84–1.60)	0.630
Depression	0.71	(0.54–0.94)	0.014

Note:

* Data available for 16,153 patients.

Table 3 The association between use of medication and the risk of developing lung cancer assessed by univariate Cox regression

Variables	Any use			Relative exposure*
	HR	95% CI	p-value	HR	95% CI	p-value
Inhaled corticosteroids**	1.06	(0.89–1.26)	0.54	0.75	(0.56–1.01)	0.06
Long-acting beta-2-agonists***	1.14	(0.96–1.35)	0.12	0.84	(0.61–1.15)	0.27
Long-acting muscarinic antagonists	1.60	(1.35–1.91)	<0.001	1.62	(1.22–2.15)	0.001
N-acetylcysteine	1.48	(1.24–1.77)	<0.001	1.59	(1.15–2.19)	0.005
Oral corticosteroids	1.88	(1.59–2.22)	<0.001	1.49	(0.92–2.43)	0.11
Statins	0.87	(1.59–2.22)	0.18	0.96	(0.66–1.39)	0.83
Bisphosphonates	1.19	(0.87–1.64)	0.27	1.32	(0.60–2.88)	0.49
ACE inhibitors	0.90	(0.73–1.12)	0.36	0.88	(0.57–1.35)	0.55
Beta-blockers	1.04	(0.87–1.25)	0.63	1.02	(0.75–1.39)	0.90
ARB	1.00	(0.78–1.27)	0.98	0.97	(0.62–1.50)	0.88
SSRI	0.79	(0.63–0.99)	0.05	0.57	(0.34–0.97)	0.04
Acetylsalicylic acid	1.37	(1.15–1.63)	0.02	1.68	(1.27–2.24)	<0.001
Diuretics	1.21	(1.03–1.44)	0.02	1.00	(0.74–1.35)	0.99

Note:

* Calculated as the proportion of days covered of the drug, during the study period.

** Alone or together with long-acting beta-2-agonists.

*** Alone or together with inhaled corticosteroids.

Abbreviations: ACE, angiotensin-converting enzyme; ARB, angiotensin II receptor blockers; SSRI, selective serotonin reuptake inhibitors.

Table 4 The independent association between demographic variables, comorbidities, and medication with the risk of developing lung cancer assessed by step wise Cox regression

Variables	HR	95% CI	p-value
Age per 10 years	1.18	(1.09–1.28)	<0.001
Asthma	0.54	(0.41–0.71)	<0.001
Inhaled corticosteroids, relative exposure*	0.52	(0.37–0.73)	<0.001
Oral corticosteroids, relative exposure*	0.45	(0.22–0.90)	0.02
Acetylsalicylic acid, relative exposure*	1.58	(1.15–2.16)	0.005
LAMA, any use	1.41	(1.17–1.70)	<0.001
N-acetylcysteine, any use	1.31	(1.09–1.59)	0.005
Oral corticosteroids, any use	2.33	(1.89–2.87)	<0.001
SSRI, any use	0.74	(0.59–0.96)	0.008
Statins, any use	0.76	(0.61–0.96)	0.02

Notes:

* Calculated as the proportion of days covered of the drug, during the study period.

Abbreviations: LAMA, long-acting muscarinic antagonists; SSRI, selective serotonin reuptake inhibitors.

Figure 1 The independent association between the relative exposure (calculated as the proportion of days covered of the drug, during the study period) of inhaled corticosteroids and the risk of developing lung cancer assessed by step wise Cox regression in relation to having or not having concurrent asthma.